Pidgin won't connect to Yahoo since June 17th? Here's a workaround

Pidgin and Yahoo

As of June 17, 2009, Pidgin users are having trouble connecting to Yahoo! IM accounts. Here is a summary of the problem:
Yahoo! appears to be upgrading their servers to a new version of their software. This new version requires a new authentication method. The latest version of Pidgin, 2.5.6, does not support this new authentication method. The next version, 2.6.0, will, but it has not yet been released.

The above link contains a set of alternate IPs (servers that are yet to be upgraded by Yahoo). Just go to Accounts -> Manage Accounts -> Modify -> Advanced -> Pager Server and try testing with those IPs. I can connect using cs101.msg.mud.yahoo.com ... for now.

UPDATE: Pidgin has released version 2.5.7, which solves this problem. Visit the Pidgin site for the update.